IROBOT RIG LABORATORY USER GUIDE
Contents
1. Laser Rangefinder Base Plates DC GND iRobot Create Figure 1 iRobot Rig University of Technology Sydney 2012 Page 3 iRobot Laboratory User Guide rem telads Version 2 2 2 Rig Specifications 2 1 Electrical Supply System The iRobot rig is powered by a fixed 24V DC supply capable of providing 150W of power The electrical supply system consists of a set of 12 tiles that are composed of inter locking plastic under layer and hot dipped zincanneal coated steel upper layer Adjacent tiles are coupled by a conducting cable with the whole layer acting as the electrical ground plane of the system Additionally there a set of 7 upper panels consisting of a steel frame and steel mesh again connected by a conducting cable to one another These upper tiles act as the positive 24V plane of the system The robot gets power from two which interface with the tiles and panels 2 2 Maze Between the upper and lower tiles forming the electrical supply system is a wooden maze which acts as the operating space for the iRobot The dimensions are shown below All dimensions are taken from the internal walls units are mm University of Technology Sydney 2012 Page 4 iRobot Laboratory User Guide Version 2 2 2 3 iRobot Create UTSE remotelabs The robotics platform used in the rig and the source of the rig s title is the iRobot Create The iRobot cr2. A screenshot of this mode is shown below Session Time In Session 00 00 44 Logging Upload iRobot 1 Remaining 00 29 16 Scanning Laser Range Finder Overhead Camera For movement you can either use the directional pad on the rig control software page to the left of the camera view by clicking or optionally clicking amp holding on the appropriate direction you want to move Other options include using the WSAD keys on your keyboard t lt arrows You can navigate the maze using any combination of the on board camera laser rangefinder or overhead camera Key D Pad Command Drive the robot forwards Drive the robot backwards ES Owe a innen _____ Turn the robot to the right Command direction is from the reference frame of the iRobot Create Take care to avoid obstacles in the maze such as walls Additionally be sure to account for any time delay between sending a command to the robot and receiving sensor data University of Technology Sydney 2012 Page 12 ursa 0 ___ 3 4 Logging Mode When the iRobot rig is in logging mode the robot operates autonomously You can enable data logging at any time regardless of whether the robot is started or not however data will not actually be logged until the robot is started A screenshot of this mode is shown below Manual 777178 Upload iRobot 1 Session Time In Sessi
3. Camera Control Overhead Camera e Step 1 Set Position amp Position Covariance On the navigation map click and drag the robot position representation icon to another position on the map close to where it actually is in our case we will move it up and to the left Once you have moved it you can adjust the covariance by dragging the square markers at each corner or you can click elsewhere on the map to go to the next step Navigation Navigation setting position covariance University of Technology Sydney 2012 Page 16 iRobot Laboratory User Guide UTS labs Version 2 2 Step 2 Set Yaw amp Yaw Covariance A line should now appear for you to set the yaw angle of the robot In our case the robot is pointing down and to the right so we will set the yaw at a similar approximation of this angle once you have an approximate yaw click on the map Once the yaw is set we must now adjust the yaw covariance you can do this by dragging the square markers at the edge of the arc or you can click elsewhere on the map to go to the next step Navigation setting yaw Navigation setting yaw covariance e Step 3 Wait amp See Within a few moments the robot should hopefully localise and begin driving around autonomously In our case success It has localised and is now navigating between waypoints by itself you are not successful at localising try the steps again or try the
4. INC UDI OIA 19 5 3 1 Providing ____________ 19 Revision History 24 05 2012 Draft Created Luke Cogar 29 05 2012 Draft Release Luke Cogar 30 05 2012 Initial Release Luke Cogar 30 05 2012 Fixed description in section 1 2 misc typographical corrections Luke Cogar 04 06 2012 Fixed descriptions removed supercded notes Luke Cogar University of Technology Sydney 2012 Page 1 iRobot Laboratory User Guide UTS labs Version 2 2 1 Introduction 1 1 Remote Laboratories Remote laboratories enable students to access physical laboratory apparatus through the internet providing a supplement to their studies and existing hands on experience Students carry out experiments using real equipment but with much greater flexibility since access can occur from anywhere and at any time Their interaction with the remote equipment is assisted by the use of data acquisition instrumentation and cameras providing direct feedback to students for better engagement Traditional engineering laboratories require students to be physically present in order to work with equipment which may limit student flexibility Conversely remote laboratories let students work in their own time and even repeat experiments for better learning outcomes Of course students cannot actually touch and feel the equipment in a remote laboratory but they can still perform most other tasks relevant to their learnin
5. Whilst the sensor is highly accurate it is subject to noise and measurement variance like any sensor Care should be taken not to interpret noise as a physical object or lack of im 90 180 270 360 Scanning Laser Range Finder Above A screen capture of laser rangefinder data showing noise University of Technology Sydney 2012 Page 18 utsa Robot Lab User Guid Robot UserGude 5 3 Contacting Support Any questions regarding the nature of assessment tasks should initially be directed to the relevant academic If the user encounters any difficulties during the course of using the rigs the Contact Support button should be used to request assistance and report an incident The following popup will appear please enter your name and a valid email address followed by a category from the Type drop down list Remote Labs Login AA lose UNIVERSITY OF RR S REMOTELABS lo 2 Login Laboratory Rigs Contact Support x The request will be sent to the Remote Labs support team Name Email Type Help Request Purpose Feedback You may then enter a brief statement regarding the nature of the request in the Purpose field Be sure to enter as detailed a description as possible of the incident in the Feedback field 5 3 1 Providing Feedback Users are strongly encouraged to leave feedback and
6. comments of their experience with the rigs to help improve the system as well as any suggestions for additional features to be included in the future Feedback can be left by clicking the Contact Support button and selecting General comment from the Type drop down list University of Technology Sydney 2012 Page 19
7. to control the robot in three different ways manually autonomously data logging or by uploading code Note If you have issues using the Rig Control Software interface please update to the latest browser The latest version of each major browser is recommended e g Internet Explorer Firefox Chrome Session Time Logging Upload iRobot 1 In Session 00 01 44 Remaining 00 58 16 Onboard Camera Scanning Laser Range Finder Figure 2 Rig Control Software with the system operating in manual mode University of Technology Sydney 2012 Page 7 UTS Robot Laboratory User Guid opot paboratory 900 3 1 Data Display The rig control software displays numerous sources of data in real time Familiarise yourself with the display and relevance of this data by reading through the sections below 3 1 1 Manual Mode 3 1 1 1 On board Camera In manual mode the on board camera is shown allowing the user to see the maze from the perspective of the robot This can be used to relate sensor data to the real world and understand the benefits and limitations of using non visual sensing systems Onboard Camera F 3 1 1 2 Laser Rangefinder In manual mode the user is also presented with a graphical representation of the laser rangefinder data The user is able to adjust the scale i e increase decrease the size and plot relationship i e rotate the view by dr
8. when this occurs In order to ensure that all components have the required supply voltage at all times adjustable 3 13 step down switching voltage regulators that maintain a fixed output voltage are used Additionally in order to provide a constant 14 8V output to the iRobot a step up step down voltage regulator is used this ensures that regardless of the electrical supply voltage i e if the battery voltage drops over time that the robot supply voltage is constant All in all the power management voltage regulation and battery system result in the iRobot rig being usable 24 hours 7 days a week with no interruptions to the user experience Specifications are given below Power Management amp Voltage Requlation Circuit Specifications Manufacturer Max Battery Charge Current Battery Charge Cutoff Voltage iRobot Supply Voltage EeePC Supply Voltage Laser Rangefinder Supply Voltage Battery Specifications Manufacturer Model Number Nominal Voltage 2 More Information A specification pack containing more information on the hardware used will be released at a later date as a downloadable archive zip file located on the session page for each rig University of Technology Sydney 2012 Page 6 UTS 0 3 Rig Control Software Once you have been allocated to a rig you should be presented with the rig control software This is an HTML5 web interface that allows you
9. UNIVERSITY OF TECHNOLOGY SYDNEY RIG LABORATORY USER GUIDE VERSION 2 1 ie TER wu uts remotelabs University of Technology Sydney 2012 iRobot Laboratory User Guide UTS labs Version 2 2 Table of Contents TE ROO 2 1 1 Remote 21 21 6 inan aan RE e RE erR idia pa TERE RA RENE ENAERE EEEE Ennni 2 1 2 iRobot The Rig Apparatus 3 2 RIO SOC CIC AO NG a s 4 2 1 Electrical Supply SY SIC 4 2 2 AAEE EEEE E E 4 2 3 OD OU Gi GC ALG sinsa ___ 5 2 4 Laser FAM SUING rsrsr e a a a E _ 5 2 5 Webcam Visual Rangefinder 5 2 6 Power Management Voltage Regulation Battery 6 2 7 Mors acct E 6 Rig Control Software 7 3 1 IS Olay A E E 8 Gell Manual 8 ee 9 o ATMO 9 3 2 Overhead Camera COmntrOl ccc
10. agging the arrows on the X and Y axes respectively Additionally you can click and drag the plot to translate it generate an offset The space between the return and the origin for each respective point are infilled in red allowing the user to easily identify obstacles such as walls By default the laser rangefinder displays data in a robot centric view that is data is displayed as the robot sees it By clicking the small rotate icon to the top left of the display the user can toggle between this default robot centric view and a world centric view In the world centric view data is displayed from a fixed reference point as if you were looking down on the robot s location but always pointing in the same direction The arrow then indicates the robots orientation in the world and the data displayed is relative to this absolute fixed reference point im im Scanning Laser Range Finder Scanning Laser Range Finder Figure 3 The laser data in robot centric view left amp world centric view with scaling amp offset right University of Technology Sydney 2012 Page 8 Version 2 2 iRobot Laboratory User Guide UTS labs 3 1 2 Logging Mode 3 1 2 1 Navigation Map In logging mode the user is presented with a representation of the map and the iRobot Create When the robot has localised its representation will turn red and it will begin path planning and driving between various waypoints in the maze These w
11. aypoints are represented by small red triangles with the goal or final waypoint having a larger red triangle overlaid The path planned for waypoint traversal is represented by a solid red line Navigation 3 1 3 All Modes 3 1 3 1 Overhead Camera In all modes the overhead camera view is displayed allowing you to see the location of the iRobot Create within the maze You can also gain an understanding of the limitations of local sensor systems i e those attached to the robot Overhead Camera University of Technology Sydney 2012 Page 9 UTSE 3 2 Overhead Camera Control The overhead camera can be controlled in two different ways depending on the needs of the user The default control method is that of Manual control whereby the user has to click and drag the red square representing the camera Field of View around the maze diagram repeatedly so as to follow find the robot The second control method is that of Automatic control whereby the rig control software uses the robot s position once known to automatically move the camera as the robot moves attempting to keep the robot in the Field of View square at all times Users can switch between modes at any time by clicking the Manual or Auto buttons on top of the camera control panel Auto Manual Camera Control Camera Control Figure 4 Camera control panel showing sele
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13. ction of Manual mode left and Auto mode right 3 2 1 Manual Control As mentioned above in manual control mode the user must manually click and drag the red Field of View square around the maze diagram so as to follow find the robot manually The images below show the relationship between the camera Field of View and the actual overhead camera image Overhead Camera F Auto Figure 5 The Field of View square centred at the origin top then moved to the lower left corner bottom University of Technology Sydney 2012 Page 10 iRobot Laboratory User Guide UTS labs Version 2 2 3 2 2 Automatic Control In automatic control mode the rig control software keeps track of the robots position once known and moves the camera automatically so that the robot is kept within the Field of View square at all times The system is fairly new and there may be some optimisations that need to be made to improve performance If you note any irregularities or performance issues please be sure to contact support Manual 777 Overhead Camera Figure 6 The robot being tracked automatically by software with the camera position adjusted accordingly University of Technology Sydney 2012 Page 11 Version 2 2 iRobot Laboratory User Guide UTS labs 3 3 Manual Mode When the iRobot rig is in manual mode you are in control You are provided with the on board camera overhead camera and laser rangefinder data
14. eate is essentially the same as the popular house cleaning robot made by iRobot the Roomba the major exception is that the Create no longer has a vacuum unit and is controllable and monitor able through the Create Open Interface The iRobot Create has a two wheel differential drive system wheel odometers bump cliff and wheel drop sensors infrared sensor and serial communications port Modifications have been made to the iRobot Create in the form of an upper and lower pantograph these are metal plates that interface with the electrical supply system providing power to the power management system voltage regulation circuit amp battery 2 4 Laser Rangefinder To complement the on board sensors a URG 04LX laser rangefinder is attached to the front of the iRobot Create The laser rangefinder allows users to retrieve extremely accurate sensor data over a wide field of view and with a large number of data points The rangefinder operates on the principle of phase shift measurement by modulating the amplitude of the emitted light and measuring the phase shift between the emission and its reflection Specifications for the unit are provided below Laser Rangefinder Specifications Hokuyo Automatic Co Ltd Operating Principle Detection Area Maximum Detection Distance 20 1000mm 10mm 1000 4000mm 1 of measurement USB Supply Voltage 5VDC Power Consumption 500mA 2 5 Webcam Visual Rangef
15. ed indicator will turn green If the robot fails to localise see Section 5 1 The robot fails to localise how can fix this If all is well the robot will begin driving around autonomously with the system logging data from the iRobot Create and its sensors as it drives around the maze To stop logging toggle the Logging On button by clicking it so that it shows Logging with red indicator optionally you can also click the Stop button so that the robot stops driving around before you change modes or begin a new logging session Note that each time a new run is started a new dataset will be generated Running Running a Running Running Running Start Start Starting Stop Stop Q Localised Localised Localised Localised Localised Logging Off Logging On Logging On Logging On Logging On Q ai Data Sets Data Sets Data Sets Data Sets Step 1 Locate the Step 2 Toggle the Step 3 Click the Start Step 4 The status Step 5 Wait for the Start button and Logging Off button so button and wait for the should now show robot to localise it will Logging button that it turns green and system to start Running with a green show Localised with a shows Logging On indicator green indicator once it has NOTE The robot will automatically stop driving autonomously and stop logging data after it has reached 7 goals If you
16. g Sometimes separation from potentially hazardous equipment is preferable from a safety point of view Due to the increased use of remote operation in industry where machinery and entire plants are often controlled from a distant location students may directly benefit from learning how to remotely control equipment Furthermore remote laboratories provide the opportunity to access a wider range of experiments as costly or highly specialised equipment may not be locally available This presents the opportunity to share laboratory facilities between institutions Significant research and pilot studies have been undertaken in Australia and by several groups around the world into the educational effectiveness of using remote laboratories These studies have consistently shown that if used appropriately in a way that is cognizant of the intended educational outcomes of the laboratory experience remote laboratories can provide significant benefits Indeed multiple research studies have demonstrated that whilst there are some learning outcomes that are achieved more effectively through hands on experimentation e g identification of assumptions specific haptic skills there are other learning outcomes that are achieved more effectively through remotely accessed laboratories e g processing of data understanding of concepts Engineering students are able to access the iRobot Rigs to help them record analyse and compare data from a range of senso
17. inder The iRobot Create is also equipped with an on board webcam that provides a near real time video feed of the operating environment from the perspective of the robot The webcam used 15 a Logitech Quickcam Pro 9000 Accuracy The webcam can also operate as a visual rangefinder whereby during logging mode the camera feed is analysed to identify the walls then transformed using the Inverse Perspective Mapping algorithm in order to estimate the distance to them The specifications for the webcam are given below Webcam Specifications Manufacturer Logitech Model Number Quickcam Pro 9000 Field of View o Effective Focal Length 2mm Maximum Resolution 1600 x 1200 2MPx USB University of Technology Sydney 2012 Page 5 iRobot Laboratory User Guide UTS labs Version 2 2 2 6 Power Management Voltage Regulation amp Battery The iRobot Create has an on board power management system as well as voltage regulation and backup battery The system was designed in house at UTS as a unique and innovative solution to providing constant power to the robot and its associated hardware As the robot moves around the maze there may be brief interruptions to the electrical supply due to the upper and or lower pantographs on the robot not making perfect contact with the conduction surface s The power management system automatically switches between the standard electrical supply 24V and the battery 14 8V
18. l be processing Partnered with am WS Y SYDNEY is y TURG gt labyshare 8 log 0528 145313 8 gt whichis WinRAR ZP archive inestrator tig Selectior Existing Reservations Reports Data Files frome http remotelabs enguuts edu eu What should Firefox do with this file Open with WinRAR ZIP defek X ut DownThemAll OneClick Ci Users 110580 Desktop O Seve File 2 After clicking the zip file title a browser specific download window should appear be sure to click Save File or similar in this window to save the file in an appropriate location on your computer University of Technology Sydney 2012 Page 15 iRobot Laboratory User Guide UTS labs Version 2 2 5 FAQ amp Troubleshooting 5 1 The robot fails to localise how can l fix this Occasionally the robot may fail to localise in the Logging mode This can happen for several reasons such as if it is too close to a wall located tightly in a corner or too close to a goal Should this happen you have two main options Firstly you can switch back to manual mode drive the robot to a different location and then switch back once more to Logging mode and begin the process again This is the simplest method Alternatively you can follow the steps below Given the robot position shown below we will attempt to re localise by giving the robot a better idea of where it is
19. manual method Oo Navigation University of Technology Sydney 2012 Page 17 iRobot Laboratory User Guide UTS labs Version 2 2 5 2 Hardware Limitations The following hardware limitations apply to the rig care should be taken to avoid mistaking real phenomena as faults and the limitations should be observed when analysing data obtained from the rig 5 2 1 iRobot Create Movement In manual mode in order to provide an easy method of control the movement of the iRobot Create has been defined in a discrete manner When the robot is commanded to drive forward it does so at a fixed velocity of 0 5 m s and when commanded to turn does so at a fixed radial velocity of 0 5 rad s Commands are issued for however long the user holds down the key on their keyboard or however long the user clicks the D Pad on screen The discretisation of the commands comes from a maximum command time of 500 ms however there may be other sources of lag in the system for example internet latency which is not constant As result of the non constant latencies the iRobot Create s movement may not be entirely repeatable users should take care when navigating the maze to account for the inherent delays and variability of movements 5 2 2 Laser Rangefinder Noise When operating in manual mode or reviewing logged data you may notice some outlying points in the laser rangefinder data This is likely noise from the sensor
20. need to collect more data for analysis purposes simply re run the exercise by following the steps above 4 1 1 Log File Contents The downloaded dataset zip contains a log file and on board camera snapshots taken every second whilst logging has been turned on the filenames of the images correlate to the time stamps of the laser 1 interface amp index The log file is formatted for use within Player Stage The table below shows the interface names and indexes and describes what the data is Interface Index Description position2d iRobot Create odometer data position2d ND nearness diagram driver data position2d Wavefront driver data laser Laser rangefinder data laser Camera laser data University of Technology Sydney 2012 Page 14 iRobot Laboratory User Guide UTS labs Version 2 2 4 2 Downloading Logged Data The logged dataset is saved as a zip file and is downloadable either during your rig session or after your rig session has concluded 4 2 1 During a Rig Session If you wish to download your logged dataset during rig session you must first ensure that logging is off You must then wait a moment for the data to be processed the log filename will appear light grey with a small clock icon to the left and be un clickable during this time Once processed the log filename will turn black and display a download icon to the left as well as a trash icon to the right Simply click the filename to d
21. on 00 06 56 00 53 04 Localised Remaining Not Logging Generate datasets by first enabling logging then starting navigation Navigation Data Sets Camera Control Overhead Camera By clicking the Start button to the left of the navigation map the robot will attempt to localise itself and if successful begin driving between various waypoints throughout the maze autonomously If the robot fails to localise please see Section 5 1 The robot fails to localise how can fix this for steps to take to resolve the issue Once you have recorded enough data you can either stop logging or stop the robot D Pad Description Drive the robot forwards za Drive the robot backwards a Turn the robot to the left gt Turn the robot to the right University of Technology Sydney 2012 Page 13 iRobot Laboratory User Guide UTS labs Version 2 2 4 Rig Data Acquisition Users are able to save data from the iRobot Create and its associated sensors Follow the procedures below carefully 4 1 Turning Data Logging On Off Whilst in the Logging mode enable logging by toggling the Logging button by clicking it such that it changes to say Logging On with a green indicator Now click the Start button the Running indicator will turn green You then need to wait for the robot to localise once it has done so the Localis
22. ownload the file A browser specific download window should then appear be sure to click Save File or similar in this window to save the file in an appropriate location on your computer You have chosen to open Logging Off Logging Off 38 og_0528_145313 2ip log 0528 145313 9 with default DownThemAll b C Users 110580 Desitop Seve File Data Sets Step 1 Ensure you turn logging off Your log file will now begin to be processed and will appear in grey text Data Sets Step 2 Once processed your log file will appear in black text with a download icon to the left and a trash Step 3 Once clicked a browser specific download window should appear Be sure to click Save File or similar in this window and with a small clock icon to the left icon to the right Click the log filename to download the file to save the file to an appropriate location on your computer 4 2 2 After a Rig Session If you have completed rig session previously and logged data you are able to retrieve the saved files by clicking the Data Files heading on the UTS Remote Labs website BSP Data Files 5 TESES A list of previously saved data files should appear to download amp save the file to your computer click the zip file title e g log 0528 145313 2 If the file does not appear it may stil
23. rs and develop simulate and test localisation and mapping algorithms University of Technology Sydney 2012 Page 2 Version 2 2 iRobot Laboratory User Guide UTS labs 1 2 iRobot The Rig Apparatus The iRobot rig was designed to allow students to explore the concepts of teleoperation of robots accuracy of sensors localisation and mapping Using a web based interface students are able to remotely control the robot and observe its movements record data provided by the different sensors compare said sensor data Additionally students can test control algorithms developed in the robot simulation software Stage by using the robot control software Player to control the iRobot create Each iRobot Rig consists of the following main components e Electrical Supply System e 1x iRobot Create 1x Laser Rangefinder 1x Webcam or Visual Rangefinder 1x Control Computer 1x UTS Remote Labs Power Management PCB 1x UTS Remote Labs Voltage Regulation PCB 1x Li ION Battery Additionally each iRobot rig is monitored by an IP camera with pan and tilt functions providing an overview of the maze The camera can operate in manual mode where the user selects which portion of the maze to view or auto mode where the robots position is automatically tracked and the camera moved to the appropriate viewpoint On board Webcam Pantograph to DC 24V EeePC Control Computer
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